There are more books and articles on the net than you can read in several lifetimes and most of them are just a google search (allinurl: .pdf) away.
For starters all the scientific papers, all the free books (out of copyright ones) and of course - to set a bad example - the pirated ones. And then there are the commercial suppliers, more like bookstores but the effect is much the same, a kindle is like an infinite bookshelf.
Then there are plenty of sources of information that are not quite books but that collectively add up to an equivalent and sometimes even more.
Subjects which are not computer related are maybe a little bit harder but not that much harder, it would be hard to find a subject that interests me (say, windmills, renewable energy, genetics) that I couldn't fill a reading list faster than I could consume it, assuming I could consume it all.
https://www.google.com/search?q=allinurl:.pdf
Says there are 1.4 billion results, now I'm sure that you should take that with a large grain of salt, for instance plenty of those pdfs are not books at all and there will be duplicates and so on. But if even 1% is unique and useful content that's 14 million volumes. I'm not aware of any normal library that I could have access to having that many books.